Submarine mine



V 1,489,508 Apnl 8 1924' H. B. PRATT SUBMARINE MINE Filed y 1923 4Sheets-Sheet 1 April 8, 1924.

H. B. PRATT SUBMARINE MINE 7 Filed May 5, 1923 4 Sheets-Sheet 5 H. B.PRATT SUBMARINE MINE April 8 1924. 1,489,508

Filed May 5. 1923 4 Sheets-Sheet 4 its SE5 ATQENT OF Free.

HARTLEY B. PRATT, OF BARROW-IN-EURNESS, ENGLAND, ASSIG-NOR TO VICKERSLIMITED, OF WESTMINSTER, ENGLAND. I

SUBMARINE MINE.

Application filed May 3,

To all whom 2'25 may concern:

Be it known that I, HARTLEY BLYlI-I PRATT, a subject of the King ofGreat Britain, residing at Naval Construction Vorks, Barrow-in-Furness,in the county of Lancaster, England, have invented certain new anduseful Improvements in or Relating to Submarine Mines, of which thefollowing is a specification.

This invention relates to submarine mines of the kind which comprise aflotation chamber, a mine proper, an anchor or sinker containing a drumon which is wound a mooring cable which connects the sinker to theflotation chamber and a plummet or sounding ball connected by a line orchain to a pawl or the like adapted to engage with ratchet teeth on thecable drum of the sinker, the weight of the plummet being adapted tohold the pawl out of engagement with the ratchet teeth during thedescent of the anchor in the water so as to allow the mooring cable tounwind, and'the plummet on touching the sea bed being adapted to allowthe pawl to engage with the ratchet teeth -so as to stop the continuedunwinding of the mooring cable; the sinker then drawing the flotationchamber beneath the surface of the water until'it assumes a depthpredetermined by the length of the line connecting the plummet to thepawl.

hen the flotation chamber requires to be anchored" at different depthsbeneath the surface of the water the length of the plummet line of eachmine has to be correspondingly increased or decreased and it is thechief object of the present invention to provide improved means forreadily and accurately varying the effective length of the plummet linefor any depth between the minimum and maximum determined by the fulllength of the plummet line. Other objects are to simplify theconstruction of the sinker casing; to provide improved means forreleasing the flotation chamber from the sinker after launching of themine and to allow the displacement of thesinker to be increased so as torender the same suitable for use in cases where a larger flotationchamberis used containing a heavier eX- plosive charge. i 1

According to one feature of the present invention adjustable means areprovided which, when set for any requlred efi'ectlve length of plummetline, act automatlcally 1923. Serial 'No. 636,295.

to stop the continued unwinding or paying 7 out of the plummet line whenthe, desired length of plummet line has been unwound.

To this end the plummet line may be Wound upon a reel carried by orattached to a screw threaded shaft which carries a' displaceable device,adapted, when the reel and shaft rotate, to travel axially along theshaft, the arrangement of the parts being such that when the nut hasbeen displaced to an extent corresponding to a predetermined length ofplummet line the nut abuts against a device which stops the continuedunwinding of the plummet line. By set-- ting the displaceable device atdifferent dis tances along the shaft the effective length of plummetline can thereby be varied as desired. .r

According to a further feature of the present invention, and in caseswhere the plummet, sinker and flotation chamber are initially heldtogether soas to constitute a single launching unit, means may beprovided, actuated by the said displaceable device for releasing anyofthe usual devices, (such as a pivoted hook which engages one end of acable connected to or surrounding the mine) which normally act to holdthe flotation chamber in contact with the sinker until after launchingof the mine.

The said displaceable device may be con- 'stituted by an internallyscrew threaded nut nel cross section, so as to prevent the nut.

rotating with the'shaft. In cases where the i said displaceable nut isalso adapted to effect the release of the flotation chamber from thesinker a pivoted lever is provided above the aforesaid fixed collar, oneend of the said lever being adapted to engage a pivoted hook which:serves to maintain the flotation chamber in position on the sinker, andthe other end being disposed in such position relatively to the arm onthe adjustingnut that it is adapted to be struck thereby when the nutreaches and abuts against the collar on the screw threaded shaft; Inorder thatvthe said invention may be clearly understood and readilycarried into effect the same will now be described more drawings, whichshow by way of example one constructional form of the said invention andin which Figure 1 is an elevation, and

Figure 2 a partly diagrammatic end view.

Figure 3 is a transverse section taken in the way of the depth settinggear.

Figure 3 is an enlarged view showing a detail of the clutch mechanism,the clutch being shown in the withdrawn position and the handle inposition thereon for depth setting purposes.

Figure 3 is a detail view of the hinged plate by which access isobtained to the clutch for depth setting purposes.

Figure 4 is a sectional elevation and Figure 5 is a sectional plan view.

A is the casing which is constituted by a single rectangular box havinga flanged base plate A The top of the casing is provided with a flangedflat plate A and the flotation chamber or mine proper B is supported onbrackets C bolted to the top plate A The side plates D carry thebearings for the mooring rope and the depth reel gear. The sides of thecasing A are closed by dished plates E, which enclose all the gearlocated outside the side plates D and handles E are provided on theplates E to facilitate removal of the side plates E to permit access tothe inside of the sinker. The rail rollers A are of the usual standardsize and rail gauge. The mooring rope drum F is of cast shafts F P oneach end thereof. In the example shown the drum is adapted to hold 1500feet of 1" cir. mooring rope G. The plummet wire reel H in the exampleshown is adapted to hold 215 feet of wire J, and the arrangement andconstruction of the depth setting gear is such as to enable themechanism to be set accurately to correspond to any depth of submersionof the flotation chamber from 5 feet up to the 215 feet. The wire J iscoiled on the reel H and from there the free end passes through a hole ain the base plate A and is connected to the plummet K. The reel H isbolted to the sleeve L and is coupled to the screw shaft M by means of aremovable clutch piece N. Owing to this arrangement and when the plummetis released the wire is unwound from the reel J which causes the shaft Mto rotate with it. As the shaft M rotates the striking lever P travelsalong the screwed shaft, the lever P being prevented from rotating bythe guide channel piece Q (Figure 4:). When the striking lever P nearsthe end of the screwed shaft M it leaves the channel guide Q but isstill prevented from rotating with the shaft by a spring controlledlever stop S, until it abuts hard up against the collar R which isrigidly secured to the shaft M. The lever P then rotates with the shaftM and passes the lever stop S. After rotating a quarter iron providedwith stub of a turn it strikes and lifts the mine release lever T whichreleases the mine release hook V, the latter in turn releasing theflotation chamber from the sinker in the usual manner. The strikinglever P then strikes and is stopped by the pawl lever W which is freelymounted in the shaft M and the Weight of the plummet acting through thereel H, the shaft M and the levers P and W, holds the pawl X out ofengagement with the mooring rope drum ratchet plate F.

When the plummet reaches sea bottom its weight no longer serves to holdback the pawl X, and the pawl spring U through the lever XV pushes thepawl X into engagement with the ratchet F and the mooring rope drum islocked in the usual manner.

The depth setting of the plummet wire is determined by the initialposition at which the striking lever P is set on the screwed shaft M,and consequently the number of turns taken by the shaft M to screw thelever P along to the collar R. A definite length of wire correspondingto the number of turns taken by the shaft M is therefore pulled off thereel J.

With the screw pitch and diameter of reel H shown on the drawing, onecomplete turn of the shaft M corresponds to 1 metre of wire wound offthe reel and a movement of the lever P along the shaft M of 5}; inch.

In order to set the striking lever P for the depth setting required thecover plate a is opened and the spring end Z) of the clutch piece N thenprotrudes thus enabling the clutch piece N to be gripped and withdrawn.The shaft M is thereby uncoupled from the sleeve L to which the depthwire reel H is bolted. A handle 0 is then inserted through the hole inthe side plate E and coupled to the shaft M as shown at Figure 3 of thedrawing. The handle is first turned to the left so as to bring the leverP hard up against the collar R as a starting point. The handle 0 is thenrotated to the right and the required number of turns given to set themechanism for the required depth, as shown by an index plate. On thehandle 0 being withdrawn and the clutch piece N replaced, the depth reelis recoupled to the screwed shaft, and the cover plate a is thenreclosed.

If it is required to rewind the depth wire on the reel the clutch pieceis removed as described above and another handle used which engages theclutch teeth on the sleeve L.

The plummet K, which is of spherical formation, is located within acasing K formed within the sinker. the casing K being open at its lowerend. The plummet K is suspended from a release lever Y which latter isconnected by a cross shaft e provided at one end with levers f and aconnecting rod 9 to a lever 72., which latter in turn is connected to afifth wheel j inthe sinker. The shaft c at its other end is coupled by alever f to a dashpot Z, and the plummet release is effected by the fifthwheel in the usual manner after'the sinker leaves the launching rails.

Subsidiary anchors is formed of bent plateof the shape shown are alsoprovided having cast iron weights Z bolted thereto. Previous to laying,the anchors 7c are retained in the position shown by locking pins mwhich are connected by a length of wire m to the flotation chamber A.After launching and'when the mine is released from the sinker the pins mare withdrawn automatically to allow the anchors tofall into work ingposition. If desired readily shearable pins may be provided which areruptured on the flotation chamber separating from the sinker. Theauxiliary wires a hold the anchors la in the best position for engagingwith the sea bed, and the anchors Z: are'so coupled to the sinker thatthey are equally effective for sinker.

A gear oil pump brake I is shown on one end of the mooring rope drumshaft, the braking action being effected by resistance pressure whichcan beadjusted as desired by blocking the passage from the delivery tothe suction side ofthe pump. A spring friction brake 0 may also beapplied as shown to the plummet wire reel H.

Thedished side plates E increase the displacement of the sinker and thisincreased displacement allows the weight of the sinker to be increasedwhile retaining the same buoyancy of the combination.

What I claim and desire to secure by Letters Patent of the United Statesis 1. A submarine mine comprising a flotation chamber, a sinker, amooring cable connecting said sinker to said flotation chamber, a drumwithin said sinker on which said mooring cable is wound, a plummet,aline connecting said plummet to said sinker the Weight of saidplummetbeing adapted to unwind said-plummet line, a device which is displacedduring the unwinding of said plummet line, adjusting means for alteringthe initial starting position of said displaceable device, and lockingmeans for the mooring cable drum which are released by said displaceabledevice when a predetermined length of plummet line is unwound so as toallow said mooring cable to unwind and the flotation chamber to separatefrom the sinker.

2. A submarine mine comprising a flotation chamber, a sinker, a mooringcable connecting said sinker to said flotation chamber, a drum withinsaid sinker on which said mooring cable is wound, locking means for saidmooring cable drum, a plummet, a plummet line, means connecting saidplumsideways dragging of the met line to said mooring cable locking"means, comprising a device which is displaced during the unwinding ofsaid 1um-' met line, said plummet when a predetermined length of plummetline has been unwound being adapted to release said mooring cablelocking means so as to allow said mooring cable to unwind and theflotation chamber to separate.

3. A submarine mine comprising a flota tion chamber, a sinker, a mooringcable connecting said sinker to said flotation chamber, a drum withinsaid sinker on which said mooring cable is wound, locking means for saidmooring cable drum, a plummet, a plummet line, the weight of saidplummet being adapted to unwind said plummet line, means for connectingsaid plummet to the mooring cable locking means comp'risinga devicewhich is continuously displaced during the unwinding of said plummetline, the

weight of said plummet when a predete'rmined length of plummet lineisunwound being adapted to unlock said mooring cable locking means so asto allow 'said mooring cable to unwind and the flotation chamber saidmooring cable drum, a plummet, a plummet line, the weight of saidplummet being adapted to unwind said plummet line, means for connectingsaid plummet to the mooring cable locking means comprising a devicewhich is continuously displaced during the unwinding of said plummetline, the

' weight of said plummet when the plummet line is unwound being adaptedto unlock said mooring cable locking means so as to allow said mooringcable to unwind and the flotation chamber to separate from the sinker,and adjustable means for varying the :in-

itial starting position of said displaceable device, the weight of saidplummet on reaching the sea bed being taken off said plummet line so asto allow the pawl to re-lock the mooring cable drum and cause the sinkerto pull the flotation chamber to a depth below the surface of the watercorresponding to the length of plummet line which has been unwound.

5. A submarine mine comprising a flotation chamber, a sinker, a mooringcable connecting said sinker to said flotation chamber, a drum withinsaid sinker on which said mooring cable is wound, a plummet, a lineconnecting said plummet to said sinker, the Weight of said plummet beingadapted to unwind said plummet line, a screw threaded shaft within saidsinker, a displaceable device mounted upon said shaft and adapted to becontinuously displaced during the unwinding of said plummet line,adjusting means for altering the initial starting position of saiddevice upon said screw threaded shaft and locking means for the mooringcable drum which are released when a predetermined length of plummetline is unwound so as to allow said mooring cable to unwind and theflotation chamber to separate from the sinker.

6. A submarine mine comprising a flotation chamber, a sinker, a mooringcable connecting said sinker to said flotation chamber, a drum withinsaid sinker on which said mooring cable is wound, a plummet, a lineconnecting said plummet to said sinker, a device which is continuouslydisplaced during the unwinding of said plummet line, locking means forthe mooring cable drum which are released when a predetermined length ofplummet line is unwound so as to allow the mooring cable to unwind andthe flotation chamber to separate from the sinker, adjusting means foraltering the initial starting position of said displaceable device, aprojecting arm connected to said displaceable device, a guide piece, theouter end of said projecting arm being located within said guide pieceso as to prevent rotation of the displaceable device.

7. A submarine mine comprisinga flotation chamber, a sinker, a reel, ascrew threaded shaft upon which said reel is mounted, a line wound uponsaid reel and connected to said plummet, a displaceable nut mounted uponsaid screw threaded shaft, adjusting means for altering the initialstarting position of said nut, a stop against which said nut abuts tostop the continued unwinding of the plummet line when a predeterminedlength thereof has been unwound, a projecting arm or lever carried bysaid nut, means for maintaining the flotation chamber in position on thesinker and means controlled by said projecting arm which operate torelease the flotation chamher from the sinker when the displaceable nuthas reached a predetermined position on the screw threaded shaft.

8. A submarine mine comprising a flotation chamber, a sinker, a reelwithin said sinker, a screw threaded shaft upon which said reel ismounted, a plummet line wound upon said reel and connected to saidplummet, a displaceable nut mounted upon said screw threaded shaft,adjusting means for altering the initial starting position of said nut,a stop against which said nut abuts to stop the continued paying out ofthe plummet line when a predetermined length thereof has been unwound, aprojecting arm carried by said nut, means for maintaining the flotationchamber in position on the sinker, means actuated by said projecting armwhich release the flotation chamber from the sinker when thedisplaceable nut has reached a predetermined position on the screwthreaded shaft, subsidiary anchors pivotally attached to said sinker,means normally holding said subsidiary anchors in contact with thesinker, and means controlled by the separation of the flotation chamberfrom said sinker for releasing said anchors and allowing the same tofall into operative position. f

9. A submarine mine comprising a flotation chamber, a sinker, a plummet,a line connecting said plummet to paying out gear in the sinker,releasing means which normally hold said flotation chamber and sinkertogether so as to constitute a single launching unit, a device which iscontinuously displaced during the paying out of the plummet line by saidpaying out gear, adjusting means for altering the initial startingposition of said device, an arm carried by said displaceable device,said arm being disposed in such position relatively tothe means whichhold the flotation chamber and the sinker together as to cause the armto actuate said releasing means when the displaceable device reaches apredetermined position.

H. PRATT.

